Several weeks ago, I was startled when taking a typical morning walk to find that a large and majestic white oak tree had been cut down and lay in the front of a neighbor’s yard. It was a shocking and sad sight, a tree I had admired almost daily, reduced to a pile of sawed-up … Continue reading A New Tree Ethic: What If Trees Really Mattered? →
It takes a practiced eye to diagnose many issues, unfortunately. That said, there’s a lot of stuff beginners can also look for.
Most helpful thing is to identify the species in question—knowing this will help you determine what a healthy example should look like. It also informs you as to the environment or care that species prefers, and if something does look abnormal, greatly narrows the potential issues.
Then I usually start with the canopy: is it full and green or discolored and sparse? Most serious issues will have be visible in the canopy, though sometimes the leaves can be damaged without serious impact on the tree.
Next you can move on to the large branches and trunk. Do they appear solid and healthy or are they soft, hollow, or decayed? Any abnormal leakage of sap or other liquid (note that for some species, sap leakage is normal). You can also look at branch attachments but that gets a little more advanced.
Finally the base and roots—these are the hardest to see but poor root health is the cause of many many problems. One thing you can easily check is whether the root flare is covered by soil or other materials—most trees should show a notable taper or flare where the trunk meets the ground. A trunk that goes straight into the ground with no flare might be buried too deep. For young trees especially, I also look for wounds at the base of the trunk. Young bark is thin and sensitive and can easily be damaged by yard equipment, which can have major effects on health and growth rate. Recent construction or grade changes can also damage the roots. Finally, it pays to look at moisture levels. Most trees like soil to be moist but not wet, though again this varies with species. I live in an arid climate, so if the weeds around the tree are dead, unless it’s a drought resistant species, it may need irrigation.
Those are some things I look out for but there is more as well. Arboriculture is a whole field of study, so there is a lot to know. But if you have specific questions, feel free to make a post to this community with some photos. I believe Treevan and myself are both arborists and there may be others lurking as well.